The subject matter disclosed herein generally relates to heat exchanger blockage detection and, more particularly, to predicting heat exchanger blockage in an aircraft based on other detected values in the aircraft.
In environments which contain high rate of particulates suspended in the air, Foreign Object Debris (FOD) can build up on the aircraft heat exchangers and degrade performance. This blockage can cause highly unstable flow through the Ram Air Fan (RAF) causing it to break (due to fan surge). Currently, some aircrafts require costly regular heat exchanger cleaning at an aggressively conservative schedule to prevent RAF damage because often there is no reliable prognostic of detecting when the ram heat exchangers are blocked with the typical aircraft sensor suite. If the blockage of a heat exchanger can be detected via a scheduled and repeatable prognostic, heat exchanger cleaning can be conducted on as needed basis vastly improving service hours and reducing cost. Further, while the performance of the system may decrease as the heat exchangers becomes blocked, the primary motivating factor to cleaning heat exchangers is preventing the RAF hardware failure.
Accordingly, there is a desire for a method and/or system with which to determine when a heat exchanger blockage has occurred or is projected to occur so that it can be remedied prior to the RAF being negatively impacted by the blockage.